Recognition of ectopic hormone syndromes produced by tumors.

Ectopic production of polypeptide hormones by tumors of nonendocrine tissues can serve as a clue to diagnosis of the tumor and as a focus for management of the patient with cancer. In the differential diagnosis of syndromes of endocrine hyperfunction, the ectopic hormone syndromes have achieved an increasingly prominent position. Available evidence on the properties of ectopic ACTH, MSH, parathyroid hormone, erythropoietin, gonadotropins, and thyrotropin is consistent with the unifying hypothesis of genetic derepression.